Embodiments of the present invention relate to methods for oxidizing carbonaceous materials and associated diesel particulate filters and exhaust gas systems.
Carbonaceous materials, such as coal, oil (e.g., diesel oil), and wood, are usually oxidized to produce energy. Sometimes, the incomplete oxidization of the carbonaceous material yields soot, which still mainly consists of carbon and is undesirable in view of environment protection. Therefore, the decrease/elimination of soot discharge is one of the lasting concerns of the public, especially in the diesel engine industry, in which the decrease/elimination of soot discharge constitutes one of the limiting factors for its development.
One approach to reduce/eliminate the soot emission of a diesel engine is the employment of a diesel particulate filter in the exhaust gas system of the diesel engine to capture and oxidize the soot from the exhaust gas. Various catalysts are developed for oxidizing soot in the diesel particulate filter.
For example, U.S. Pat. No. 7,797,931 discloses a catalyst composition for use on a diesel particulate filter for facilitating soot oxidation comprising a catalytic metal comprising a platinum group metal selected from Pt, Pd, Pt—Pd, and combinations thereof. The cost of the platinum group metals is high.
Other currently available methods for oxidizing carbonaceous materials and associated diesel particulate filters and exhaust gas systems do not satisfactorily meet the existing needs either, so it is desirable to develop a new method for oxidizing carbonaceous material and associated diesel particulate filter and exhaust gas system.